#include <fstream>
#include <set>
#include <algorithm>
#define DIM 50010
#define p second
#define t first
#define INF 1000010
using namespace std;

multiset<int> s;
pair<int, int> v[DIM];
int x[DIM];
long long d[DIM];

int n, k, total, sum;

int main () {
    ifstream fin ("peste.in");
    ofstream fout("peste.out");
    fin>>n>>k>>total;
    for (int i=1;i<=n;i++) {
        fin>>v[i].second>>v[i].first;
    }
    sort(v+1, v+n+1);

    x[0] = -INF;
    int j = 1;
    for (int i = 1;i<=v[n].t;i++) {
        if (i < v[j].t) {
            x[i] = x[i-1];
        } else {
            while (j<=n && v[j].t == i) {
                s.insert(v[j].p);
                sum += v[j].p;
                j++;
            }
            while (s.size() > k) {
                sum -= *s.begin();
                s.erase(s.begin());
            }
            x[i] = sum;
        }
    }

    d[0] = 0;
    for (int i=1;i<=total;i++) {
        d[i] = -INF;
        for (int last = 1; i-last+1 >= 1 && last <= v[n].t; last++) {
            if (d[i-last] + x[last] > d[i])
                d[i] = d[i-last] + x[last];
        }
    }
    fout<<d[total];
    return 0;
}